The Best Plants to Grow in Aquaponics Systems

If you’ve landed on this page, maybe you’re one of the many people interested in growing their own food. Maybe you’ve even heard of aquaponics—and you’re curious to know how they work, and what plants they can grow.

Hydroponics involves growing plants in water rather than soil, and aquaculture is the cultivation of fish. Together they work in symbiosis, helping each other out.

The basic setup of aquaponics systems is that plants grow of top of water, where one or more fish live. You feed the fish, and the fish poop in the water, as fish do. The waste builds up over time, which is normally quite toxic to the fish. However in this system, the plants growing on top dangle their roots into the water, and absorb the waste.

The fish poop is high in nutrients like nitrogen, and the plants use it as fertilizer. This means the plants have fertilizer that is pretty much free—no need to add any extra to the water. And at the same time, the plants purify the water for the fish, providing them with a clean home! This makes frequent water changes unnecessary. So you feed your fish, the fish waste becomes fertilizer, your plants grow well, and you get to eat the plants anytime you want. Needless to say: in aquaponics, there’s winning all around.

While modern aquaponics is gaining in popularity, it’s not exactly new

Its ingenuity can actually be traced back to Aztec Indians, who used this neat little system in Central America. As early as 1000 AD, they were growing plants on rafts that floated on lakes full of fish. Rice paddies in Asia were also early aquaponics systems, and they still exist today. Modern aquaponics in the US is usually done indoors—so another major benefit is that plants and fish can be raised year-round in almost any part of the world.

Photo courtesy of Sidewalk Sprouts

In today’s aquaponics systems, plants usually grow on top of a fish tank. Depending on how you see them, they might look beautiful, or a little funny at first. But combining these two systems is a really cool and efficient system. The benefits of both hydroponics and aquaculture are maximized, and their drawbacks are reduced.

Small Systems vs. Large Systems

If you’re thinking of getting your own aquaponics setup going, you are probably wondering: what plants can I grow?

The bottom line is the best plants to grow in your aquaponics system depends on its size. A small system will have fewer fish, less waste, and therefore lower nutrient concentrations. Larger systems have more fish, more waste, and higher nutrient concentrations. This difference affects the types of plants you can grow in your system.

A small, less nutrient-dense system is best for plants that need lower nutritional inputs, like greens and herbs. Plants that can grow in small aquaponics systems include:

lettuce

kale

spinach

Swiss chard

arugula

mint

chives

basil

watercress

pak choi

wheatgrass

radish sprouts

Small systems can grow herbs and greens for your salads. So if you’re not quite ready to take the plunge in to aquaponics with a large system, but you still want to try it, a small tank might be the perfect place to start.

We have lovely little aquaponics tank, called the Water Garden 2.0, that comes with nearly everything you need.

Larger aquaponics systems are so big that they need to be kept in greenhouses (which some people even do in their backyards). These more nutrient-dense systems can grow plants that have both low-nutrient and high-nutrient requirements. Large systems can grow the greens and herbs listed above, in addition to larger plants such as:

tomatoes

peppers

cucumbers

beans

squash

peas

proccoli

cauliflower

cabbage

Simply put, larger, fruiting plants and legumes need a lot of energy and nutrients. It takes a lot of nitrogen, phosphorus and potassium for plants to grow tomatoes, peppers, and cucumbers, or even broccoli and cauliflower. Since more fish means more nutrients, bigger aquaponics systems will support the growth of these bigger plants.

Home Gardening with Aquaponics

While the phrase “home gardening” might conjure images of pots of tomatoes on a fire escape, or backyard vegetable gardens, times are changing. Gardening technologies are improving, and new products are released every year to assist people everywhere in their home gardening adventures. Home gardeners can get small aquaponics systems set up in their homes, at relatively low costs. An aquaponics system may be as small as a fish tank that sits on your counter or windowsill. With a charismatic betta fish, and fresh greens growing on top of its tank, they are super pretty to look at (not to mention a conversation starter). They are also lower-maintenance than a regular fish tank.

With more space, money and time, aquaponics systems can be scaled up. Large ones will grow big, lush plants. They can even support fruiting plants like tomatoes, peppers and cucumbers. In fact, larger operations can produce quite a bit of food—enough to majorly supplement your family’s diet, or stock stands at local farmer’s markets.

Whether you decide to invest in a small or large system, they’re an attractive, efficient, environmentally-friendly option for enjoying fresh food year-round.